glad Loader-Generator

To run the gl-glfw-mx example, you must first run the init.sh script to generate the glad-gl crate into the build/ directory, then execute the project using cargo run.

./init.sh && cargo run

To run the gl-glfw example, you must first generate the glad-gl crate using the provided initialization script and then execute the cargo project.

./init.sh && cargo run

To generate the specific loader files required for your project (Vulkan, GL, GLES, EGL, GLX, or WGL) in multiple languages, use the official glad2 web service. This is the recommended way to obtain the generated source code tailored to your specific API requirements.

https://glad.sh

The repository contains various implementation examples for different APIs and windowing libraries. Key examples include:

C/C++

• GL with GLFW (standard and on-demand loading)
• GL with SDL2 and SDL3 (including callbacks)
• Vulkan with GLFW
• Platform-specific loaders: GLX, WGL, and EGL X11

Rust

• GL with GLFW (standard and multiple windows/contexts)

The gl-glfw example uses a locally generated glad-gl crate located in the build/ directory. When setting up a similar project, reference the dependency in your Cargo.toml as follows:

[dependencies]
glad-gl = { path = "./build/glad-gl" }

When using the --api flag, you can specify exact versions and profiles using the following syntax:

• name:profile=version (e.g., gl:core=3.3)
• name:profile/spec=version (e.g., gles1/gl=2)

If no version is provided, the latest version is used. A profile is only mandatory if the specific API requires one.

When using the glfw crate in Rust, you can initialize glad by calling gl::load. You must provide a closure that maps OpenGL function pointers to the addresses provided by glfw.get_proc_address_raw.

gl::load(|e| glfw.get_proc_address_raw(e) as *const std::os::raw::c_void);

When using GLFW, you must include glad/gl.h before any other graphics headers (like GLFW/glfw3.h). To initialize the OpenGL context, call gladLoadGL passing the glfwGetProcAddress function. If the returned version is 0, initialization failed. You can retrieve the loaded version using the GLAD_VERSION_MAJOR and GLAD_VERSION_MINOR macros.

#include <glad/gl.h>
// GLFW (include after glad)
#include <GLFW/glfw3.h>


int main() {
    // -- snip --

    GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "LearnOpenGL", NULL, NULL);
    glfwMakeContextCurrent(window);

    int version = gladLoadGL(glfwGetProcAddress);
    if (version == 0) {
        printf("Failed to initialize OpenGL context\n");
        return -1;
    }

    // Successfully loaded OpenGL
    printf("Loaded OpenGL %d.%d\n", GLAD_VERSION_MAJOR(version), GLAD_VERSION_MINOR(version));

    // -- snip --
}

To use glad with the glfw crate in Rust, you need to initialize glad by providing a loader function that maps OpenGL function pointers to the addresses provided by glfw.

Use the gl::load method with a closure that calls glfw.get_proc_address_raw(e) for each entry e.

gl::load(|e| glfw.get_proc_address_raw(e) as *const std::os::raw::c_void);